1. Field of the Invention
The invention relates generally to massage chairs and, more particularly, to a massage chair that uses reclining movement of a backrest for stretching user's arms.
2. Description of the Related Art
Such a massage machine is described in, for example, Japanese Patent Application Publication No. 2005-013463 issued Jan. 20, 2005. This machine (hereinafter referred to as a “first prior art”) uses an electric reclining mechanism of a backrest to obtain a stretching (extension) effect on the user's arms. That is, the first prior art swells left and right airbags located at each of left and right armrests to hold each forearm of the user with each left and right airbags, and moves the backrest into a final position from a start position to lean the upper part of the user's body backward. The start position is a sloping position, and the end position is a sloping position that has an inclination larger than the start position with respect to the vertical direction. While holding each forearm with each left and right airbags, the first prior art repeatedly drives the electric reclining mechanism so that the backrest is moved into the final position and returned to the start position (initial angle).
Another massage machine described in Japanese Patent Application Publication No. 2005-152260 issued Jun. 16, 2005 also uses an electric reclining mechanism of a backrest to obtain a stretch effect on the user's arms and shoulders. This machine (hereinafter referred to as a “second prior art”) swells upper and lower airbags located at each of left and right arm rests to hold each hand and forearm of the user with each upper and lower airbags, and moves the backrest into a final position from a start position to lean the upper part of the user's body backward. In case of a first operational example, the second prior art moves the backrest into the final position while swelling the airbags of the armrests; returns the backrest to the start position after the airbags finish swelling; and shrinks the airbags after holding each swollen condition of the airbags for a specified time. In case of a second operational example, the second prior art swells the airbags of the armrests; moves the backrest into the final position after the airbags finish swelling; and returns the backrest to the start position while shrinking the airbags after holding each swollen condition of the airbags for a specified time.
However, each of the first and second prior arts moves its backrest into final position from a start position without stopping, and therefore uses strength in response to the final position to pull the user's arms without stopping.